ATTO 490 LS Carboxy LS-Dye Series 1 mg

Optical properties

• λ _abs = 496 nm
• ε _max = 4.0×10⁴ M ^-1 cm ^-1
• λ _fl = 661 nm
• n _fl = 30 %
• τ _fl = 2.6 ns
• CF ₂₆₀ = ε ₂₆₀ /ε _max = 0.37
• CF ₂₈₀0 = ε ₂₈₀ /ε _max = 0.18

ATTO 490LS is a new fluorescent label featuring an extraordinary large Stokes-shift of 165 nm. Thus the emission spectrum is almost completely separated from the absorption spectrum, making the dye highly suitable for multicolor experiments, in particular in combination with ATTO 488 and ATTO 514.

ATTO 490LS is very hydrophilic, highly water soluble, and exhibits a relatively high fluorescence quantum yield, which is only slightly reduced on conjugation to biomolecules, e.g. proteins, even at high degrees of labeling (DOL).

ATTO 490LS is an anionic dye. After conjugation to a substrate the dye carries a net electrical charge of -1. The fluorescence is excited most efficiently in the range 460 - 530 nm.